1. Field of the Invention
The present invention relates in general to the testing of semiconductor devices and, in particular, to the use of existing test and burn-in infrastructure for the testing of a known good die (KGD) which is a bare, unpackaged die that has been tested to the equivalent of a packaged and fully tested semiconductor device.
2. Brief Description of the Prior Art
At present, there is no good low cost and low volume approach to production of KGD that uses the existing test and burn-in infrastructure. If the semiconductor die requires burn-in to insure the reliability of the device, expensive die test carriers and special test and burn-in tooling are required for the production of KGD.
Currently, the state of the art for testing KGD devices requires that the die be temporarily held in a test jig of some form in order to establish electrical contact between the input and output (input/output) pads on the device under test (DUT) and the test instrumentation. At this level, this has previously been accomplished in the art by one of two procedures. One technique, “soft” tape automatic bonding (TAB), requires making a temporary bond to the DUT input/output pads. This can give rise to considerable damage to the pads after removal. The second method for holding the DUT in a test assembly is to use a carrier in the form of an MCM with probe tips formed from hard metal bumps. The probe tips on the modules are arranged in a pattern to exactly match the positions of the input/output pads on the DUT. The DUT is aligned with the probe tips by means of either a mechanical “alignment fence” or an optical technique. Because the probe tips are not sufficiently planarizing over the surface of the die, large forces are required in order to insure good electrical contact with every input/output pad on the die. The hard metal probe tips may damage the pads. Because of the cost associated with KGD testing and quality problems posed by the “soft TAB” and MCM methods, there is a need in the art for an improved test assembly for the testing of KGD.